Generally, a multi-type air conditioning system having a single heat source unit connected to plural load units in parallel via two refrigerant pipes has been known. The aforementioned air conditioning system is formed of the heat source unit including a compressor, a four-way selector valve and an outdoor heat exchanger (a heat source heat exchanger), and the load unit including a throttle and an indoor heat exchanger (a load heat exchanger). The above-structured air conditioning system allows the respective load units to perform such operations as hot water supply, cooling, and heating selectively and independently. In other words, the system allows one indoor unit to perform the cooling, another indoor unit to perform the heating, and still another indoor unit to perform the hot water supply simultaneously.
There has been introduced an air conditioning system in which a single heat source unit, which is formed of a refrigerant compressor, a four-way selector valve, a heat source heat exchanger, an accumulator, a refrigerant flow passage selector unit, and the like, is connected to at least one indoor unit, which is formed of an indoor heat exchanger, a first refrigerant flow controller, and the like, and to at least one first water temperature controller, which is formed of a first water consuming side heat exchanger to perform heat exchange between the refrigerant from the heat source unit and water fed to the water consuming unit, a water consuming side refrigerant flow controller, and the like, in parallel via first and second connector pipes, and the first branch portion and the second branch portion are connected via the second refrigerant flow controller. The first branch portion includes a switch valve which selectively connects one of refrigerant outlet/inlet of the indoor heat exchanger for the indoor unit, or one of refrigerant outlet/inlet of the heat exchanger for the first water consuming unit to the first or the second connector pipe. The second branch portion connects the other of the refrigerant outlet/inlet of the heat exchanger for the indoor unit or the other of the refrigerant outlet/inlet of the heat exchanger for the first water consuming unit to the second connector pipe via the first refrigerant flow controller (see Patent Document 1).
This air conditioning system does not have to be equipped with two heat source units for air conditioning and for water heating, respectively, and allows the respective indoor units to perform operation for the hot water supply, cooling, and heating with the simple structure. This makes it possible to reduce the costs for preparing such facility as the heat source unit for heating water and maintaining the operation. The system allows efficient re-use of the exhaust heat generated in the cooling operation through the first water temperature controller especially in the intermediate season like spring and autumn when both the cooling and heating operations are likely to be performed. This makes it possible to reduce the energy consumption.    [Patent Document 1] Japanese Unexamined Patent Application publication No. 8-261599 (p. 4, FIG. 1)